fix(amazonq): Prompt re-authenticate if auto trigger failed with expired token

[leigaol]

Problem

As inline completion was moved to Flare LSP, one previous design of inline completion: Show re-auth prompt when access denied, was not migrated.

Solution

Prompt re-authenticate if auto trigger failed with expired token.
This is not new code, I just borrowed old code path. Link is added in the comments.

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